EP0711869A2 - Multi-layer headbox - Google Patents

Multi-layer headbox Download PDF

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Publication number
EP0711869A2
EP0711869A2 EP95117555A EP95117555A EP0711869A2 EP 0711869 A2 EP0711869 A2 EP 0711869A2 EP 95117555 A EP95117555 A EP 95117555A EP 95117555 A EP95117555 A EP 95117555A EP 0711869 A2 EP0711869 A2 EP 0711869A2
Authority
EP
European Patent Office
Prior art keywords
lamella
headbox according
tip
machine
headbox
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP95117555A
Other languages
German (de)
French (fr)
Other versions
EP0711869B1 (en
EP0711869A3 (en
Inventor
Wolfgang Ruf
Frank Fey
Thomas Dietz
Klaus Pimiskern
Gerhard Wernlein
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Voith Patent GmbH
Original Assignee
Voith Sulzer Papiermaschinen GmbH
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Publication date
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Publication of EP0711869A2 publication Critical patent/EP0711869A2/en
Publication of EP0711869A3 publication Critical patent/EP0711869A3/en
Application granted granted Critical
Publication of EP0711869B1 publication Critical patent/EP0711869B1/en
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    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
    • D21F1/00—Wet end of machines for making continuous webs of paper
    • D21F1/02—Head boxes of Fourdrinier machines
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
    • D21F1/00—Wet end of machines for making continuous webs of paper
    • D21F1/02—Head boxes of Fourdrinier machines
    • D21F1/028—Details of the nozzle section
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
    • D21F9/00—Complete machines for making continuous webs of paper
    • D21F9/003—Complete machines for making continuous webs of paper of the twin-wire type
    • D21F9/006—Complete machines for making continuous webs of paper of the twin-wire type paper or board consisting of two or more layers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S162/00—Paper making and fiber liberation
    • Y10S162/09—Uses for paper making sludge
    • Y10S162/10—Computer control of paper making variables
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S162/00—Paper making and fiber liberation
    • Y10S162/09—Uses for paper making sludge
    • Y10S162/10—Computer control of paper making variables
    • Y10S162/11—Wet end paper making variables

Definitions

  • the invention relates to a multi-layer headbox with the features specified in the preamble of claim 1. These are known from DE 43 29 810 A1 (file PA05205).
  • the function of the lamella in a multi-layer headbox is to keep the two material flows so separate that no mixing of the different flows takes place, until finally the flows are combined in as undisturbed form as possible into a single flow, with as little interference as possible this flow pattern may occur.
  • Various approaches have been taken to avoid this flow disturbance.
  • the applicant proposed to design the lamella so that there is an increased convergence in the flow channel, so that an increase in the flow velocity in this area results in a reduction in the disturbances due to friction turbulence .
  • the end of the lamella could not be made very sharp for reasons of manufacturing technology, costs and operational safety.
  • a blunt lamella end in turn means that turbulence or periodic detachment of turbulence occurs, and that vibrations are subsequently transmitted to the lamella end or to the entire lamella.
  • This creates disturbances in the formation of the paper web and / or undesirable local mixing of neighboring material flows.
  • the result is that in the finished multi-ply paper, the layers in some places no longer clearly differentiate from each other, e.g. B. in terms of different colors.
  • the strip or strips or strip segments specified in claims 1 to 7 can preferably be produced from a hard ceramic material. Such ceramic strips are free of internal tension, so that the finished slat is extremely dimensionally stable. However, it is also possible to use metals (e.g. titanium) for the strips. In this case, however, mechanical processing is usually required, with the risk that internal stresses arise in the strips or strip segments. The consequence of this may be that the tip area of the finished lamella does not extend straight with the required accuracy.
  • metals e.g. titanium
  • claim 8 states the following: the end region of the main lamella part is given a shape that tapers towards the end, this end region is provided with a coating made of a hard material (for example, a metal sheet) that forms the tip, and then processed End area such that an essentially sharp pointed edge is created. This processing is again preferably carried out by grinding.
  • a coating made of a hard material for example, a metal sheet
  • This processing is again preferably carried out by grinding.
  • FIG. 1 shows a schematic cross section through a two-layer headbox.
  • FIG. 2 is a view of the exit gap of the headbox in the direction of arrow II in FIG. 1.
  • Figures 3 to 8 show different versions of the slat end area in a greatly enlarged representation compared to the natural dimensions, each in cross section.
  • FIG. 1 From a two-layer headbox known per se, essentially only the area of the so-called nozzle chamber can be seen, which leads two machine-wide material flows to an exit gap.
  • the nozzle chamber is delimited by two machine-wide flow guide walls 1 and 1 'and by two side walls 6 and 6', see FIG. 2.
  • the two flow guide walls 1 and 1 ' are each connected to a central stationary partition 7 via a known turbulence generator 5.
  • a lamella 2 is pivotally attached, for example by means of a joint 4. Deviating from this, the lamella 2 can also be rigidly attached to the partition 7.
  • the lamella 2 extends from the joint 4 to the region of the outlet gap or beyond it.
  • FIG. 1 the lamella 2 extends from the joint 4 to the region of the outlet gap or beyond it.
  • the lamella extends over the entire machine width, that is to say directly from one side wall 6 to the other side wall 6 '. Consequently the lamella 2 keeps the two material flows indicated by the arrows 3 and 3 'separated from one another up to the region of the outlet gap. Deviating from FIGS. 1 and 2, a plurality of lamellae can be provided for more than two machine-wide material flows to be separated from one another.
  • the components of the headbox described so far are very precisely manufactured in a known manner, so that the clear width a of the entire outlet gap is uniform over the machine width. If necessary, a locally deformable strip is provided on the wall 1 in order to even out the clear width a of the outlet gap.
  • the lamella 2 and in particular its tapered end which is located in the area of the outlet gap, also very precisely.
  • the tapering fin end must run as straight as possible from one side wall 6 to the other side wall 6 ', and possibly exactly parallel to the outlet ends of the flow guide walls 1 and 1'. It is crucial for achieving high paper quality that the clear widths b and c of the two partial exit gaps are as constant as possible over the entire machine width.
  • FIGS. 3 to 8 This goal is achieved by means of various special configurations of the lamella tip, illustrated as an example in FIGS. 3 to 8.
  • the thickness d of the slat is increased considerably more than the dimensions in the longitudinal direction, for example to clarify the details, for example the length L of the strip 9.3 which forms the tip of the slat according to FIG. So in reality the angle w is the pointed edge much smaller than shown in the drawing. The pointed edge is more like a knife-like edge.
  • the lamella tip is formed from a preformed one or two-part strip 9.3, 9.4 or 9.5.
  • the strip 9.3 is glued into a groove of the main part 8.3 of the lamella by means of an integrally formed web.
  • FIG. 4 shows a reverse example: Here, a web of the main part 8.4 of the lamella projects into a groove in the strip 9.4 forming the tip; this can also be made in two parts, similar to FIG. 5.
  • a thin metal sheet 9.6 is attached to the end of the main lamella part 8.6. Viewed in cross section, the metal sheet 9.6 projects beyond the free end of the main lamella part 8.6; it is by means of mechanical processing, e.g. B. grinding, provided with a sharp pointed edge. In the event of damage, this can be reground. If necessary, the entire slat end can be provided with a uniform inclined surface, e.g. b. Loops along the level S.
  • both sides of the tapering end of the main lamella part 8.7 are provided with a hard outer layer 9.7 and then provided with a sharp pointed edge by grinding along the plane S '.
  • both sides of the tapered end of the main lamella part 8.8 are again coated with thin metal-sheet strips 9.8 and 9.8 'of different widths. It is essential that one metal strip 9.8 'projects beyond the other 9.8 so that this alone forms a sharp pointed edge produced by grinding.
  • the entire lamella is made chemically resistant to a large extent to the material suspension.
  • the outer surfaces of the lamella touched by the fabric have a permanently high level of smoothness, so that fibers or other material particles are reliably prevented from getting caught.
  • the outer surface of the lamella preferably also has smooth transitions from the main part (preferably made of plastic) to the tip. Under certain circumstances, however, a level 10 can also be provided at a transition; see Figure 5.
  • the lamella main part is made of a plastic reinforced with carbon fibers (claim 17).
  • a plastic reinforced with carbon fibers (claim 17).
  • Such a material gives the main part of the slats a very high thermal stability.
  • the shape of the lamella main part remains unchanged even if it comes into contact with (possibly differently) heated fiber suspension streams.
  • the uniformity of the shape of the lamella end is significantly increased, mainly in connection with the lamella tip formed by a relatively thin coating.
  • a locally deformable strip can be provided on one of the current guiding walls 1 or 1 '.
  • Such a bar also called “aperture”
  • aperture has long been known as a tool to even out the basis weight cross profile of the paper web to be produced.
  • problems arise in the production of multilayer paper webs, in particular if emphasis is placed on a cover layer which is as thin as possible and which at the same time should cover the layer underneath very uniformly. If a local deformation of the aperture of the headbox is carried out, the material jet emerging from the headbox is deformed. The thickness of the Influenced outer layer, which should actually remain the same thickness.
  • an orifice adjustment device also means that the headbox nozzle, particularly when used in conjunction with twin-wire formers, cannot be brought close enough to the wire, which means that an undesirably long, unguided material jet has to be accepted , which is particularly noticeable in the case of multilayer papers.
  • lamella which has a sharp pointed edge
  • headbox which has no deformable strip, screen or the like.
  • the nozzle end of the headbox can be designed very simply and therefore requires little effort in terms of production technology.
  • the headbox can be brought very close to the screen or between the screens, which greatly shortens the free jet of fabric and thus further increases the quality of the multilayer paper to be produced.
  • FIG. 9 shows the headbox, which has already been described above with reference to FIG. 1, together with a schematically illustrated line system for feeding various fiber suspensions.
  • a first main material stream consisting of a first type of paper stock, reaches a one of the two turbulence generators 5 via a cross distribution line 11 and a branched branch row of section feed lines 13.
  • a second main stock stream consisting of another type of paper stock, reaches a cross distribution line 12 and over a branched series of sectional Feed lines 14, 14 'to the other turbulence generator 5.
  • a third cross distribution line 15 is provided for feeding a so-called secondary material flow. This consists, for. B.
  • a plurality of sectional supply lines 16, each with a control valve 17, are branched off from the transverse distribution line 15.
  • Each of the lines 16 thus leads a controllable sectional secondary material flow to a mixing point 18, where it is mixed with one of the sectional main material flows.
  • further feed lines for individually controllable sectional secondary material flows could open into the sectional feed lines 13 for the first main material flow.

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  • Paper (AREA)
  • Magnetic Heads (AREA)
  • Production Of Multi-Layered Print Wiring Board (AREA)

Abstract

A multilayer breast box is for feeding at least two machine-wide pulp suspension currents to the forming section of a paper machine. It has a nozzle chamber defined by two current guide walls (1), which end at a machine-wide discharge gap, and by two side walls. The nozzle chamber contains at least one lamella (2) with the function of a partitioning which keeps the fibre suspension currents apart from each other in the discharge gap section. The lamella (2) comprises a main section, preferably made of carbon fibre-reinforced plastics, and a tip made of a rigid material. The tip takes the form of a strip which has a sharp edge and is integrated into the main section.

Description

Die Erfindung betrifft einen Mehrschichten-Stoffauflauf mit den im Oberbegriff des Anspruches 1 angegebenen Merkmalen. Diese sind bekannt aus DE 43 29 810 A1 (Akte PA05205).The invention relates to a multi-layer headbox with the features specified in the preamble of claim 1. These are known from DE 43 29 810 A1 (file PA05205).

Die in einem Mehrschichten-Stoffauflauf befindliche Lamelle hat die Aufgabe, die beiden Stoffströmungen so getrennt zu halten, daß keine Vermischung der unterschiedlichen Strömungen zustande kommt, bis schließlich die Strömungen in möglichst ungestörter Form zu einer einzigen Strömung vereinigt werden, wobei gleichzeitig möglichst keine Störungen in diesem Strömungsverlauf auftreten dürfen. Besonders zu beachten ist hierbei das Ende der Lamelle, da dieser Bereich sehr häufig den Ursprung von Strömungsstörungen bildet. Zur Vermeidung dieser Strömungsstörung wurden verschiedene Ansätze unternommen. Unter anderem wurde gemäß DE 43 23 050 A1 (Akte PA05153) der Anmelderin vorgeschlagen, die Lamelle so zu gestalten, daß sich eine erhöhte Konvergenz im Strömungskanal ergibt, so daß durch Erhöhung der Strömungsgeschwindigkeit in diesem Bereich sich eine Verminderung der Störungen aufgrund von Reibungsturbulenz ergibt.The function of the lamella in a multi-layer headbox is to keep the two material flows so separate that no mixing of the different flows takes place, until finally the flows are combined in as undisturbed form as possible into a single flow, with as little interference as possible this flow pattern may occur. Particular attention should be paid to the end of the lamella, as this area very often forms the origin of flow disturbances. Various approaches have been taken to avoid this flow disturbance. Among other things, according to DE 43 23 050 A1 (file PA05153) the applicant proposed to design the lamella so that there is an increased convergence in the flow channel, so that an increase in the flow velocity in this area results in a reduction in the disturbances due to friction turbulence .

Bezüglich der konstruktiven Gestaltung des Endes der Lamelle war man bisher der Ansicht, daß das Ende der Lamelle aus Gründen der Fertigungstechnik, Kosten und Betriebssicherheit nicht sehr scharf gemacht werden kann. Ein stumpfes Lamellen-Ende hat aber wiederum zur Folge, daß Turbulenzen bzw. periodische Ablösungen von Turbulenzen entstehen, und daß in der Folge sich Schwingungen auf das Lamellenende bzw. auf die gesamte Lamelle übertragen. Hierdurch entstehen Störungen bei der Formation der Papierbahn und/oder unerwünschte örtliche Vermischungen benachbarter Stoffströme. Die Folge ist, daß in dem fertigen Mehrlagen-Papier die Lagen sich an manchen Stellen nicht mehr deutlich voneinander unterscheiden, z. B. hinsichtlich unterschiedlicher Farben.With regard to the structural design of the end of the lamella, it was previously believed that the end of the lamella could not be made very sharp for reasons of manufacturing technology, costs and operational safety. However, a blunt lamella end in turn means that turbulence or periodic detachment of turbulence occurs, and that vibrations are subsequently transmitted to the lamella end or to the entire lamella. This creates disturbances in the formation of the paper web and / or undesirable local mixing of neighboring material flows. The result is that in the finished multi-ply paper, the layers in some places no longer clearly differentiate from each other, e.g. B. in terms of different colors.

Man hat versucht, diese Nachteile dadurch zu vermeiden, daß gemäß DE '810 an einem im wesentlichen stumpfen Lamellen-Ende Schlitze oder Nuten vorgesehen werden, oder daß eine über das Lamellen-Ende hinausragende dünne Folie angeordnet wird. Diese Maßnahmen haben jedoch noch nicht voll befriedigt.Attempts have been made to avoid these disadvantages by providing slots or grooves in accordance with DE '810 at an essentially blunt lamella end, or by arranging a thin film which projects beyond the lamella end. However, these measures have not yet been fully satisfied.

Der Erfindung liegt deshalb die Aufgabe zugrunde, das Lamellen-Ende eines Mehrschichten-Stoffauflaufes derart zu gestalten, daß die nachfolgend angegebenen Forderungen möglichst weitgehend erfüllt sind:

  • 1. Das Lamellen-Ende soll über die gesamte Maschinenbreite eine möglichst gleichmäßige Form aufweisen, so daß die lichte Höhe jedes der durch die Lamelle getrennten Strömungskanäle über die Maschinenbreite möglichst exakt konstant ist.
  • 2. Zur Vermeidung von Wirbelablösungen am Lamellen-Ende soll dieses sich möglichst schlank verjüngen und eine relativ scharfe, schneidenartige Kante aufweisen.
  • 3. Die genannte, relativ scharfe Kante soll möglichst unempfindlich gegen mechanische Beschädigungen sein und/oder nach einer eventuellen Beschädigung nachbearbeitbar sein (z. B. durch Schleifen). Dies ist besonders dann wichtig, wenn die Lamelle über den Austrittsspalt aus dem Stoffauflauf herausragt.
The invention is therefore based on the object of designing the fin end of a multilayer headbox in such a way that the requirements specified below are met as far as possible:
  • 1. The slat end should have a shape that is as uniform as possible over the entire machine width, so that the clear height of each of the flow channels separated by the slat is as constant as possible over the machine width.
  • 2. To avoid vortex detachment at the end of the lamella, the end should taper as slim as possible and have a relatively sharp, knife-like edge.
  • 3. The relatively sharp edge mentioned should be insensitive to mechanical damage as far as possible and / or be reworkable after any damage (eg by grinding). This is particularly important if the lamella protrudes from the headbox via the outlet gap.

Diese Aufgabe wird gemäß der Erfindung mit den im Anspruch 1 oder mit den in Anspruch 8 angegebenen Maßnahmen gelöst. Beiden Lösungen ist gemeinsam, daß die aus einem Hartwerkstoff gebildete Spitze der Lamelle - entgegen den bisherigen Vorstellungen - mit einer relativ scharfen, schneidenartigen Spitz-Kante versehen ist. Man hat nämlich erkannt, daß es mehrere (in den Ansprüchen einzeln angegebene) Möglichkeiten gibt, die an dem Hauptteil der Lamelle befestigte Spitze derart auszubilden, daß sie - nach sicherem Befestigen am Hauptteil - durch mechanisches Bearbeiten mit einer scharfen Spitz-Kante versehen werden kann.This object is achieved according to the invention with the measures specified in claim 1 or with the measures specified in claim 8. Both solutions have in common that the tip of the lamella made of a hard material - contrary to previous ideas - with a relatively sharp, knife-like pointed edge is provided. It has been recognized that there are several possibilities (individually specified in the claims) to design the tip fastened to the main part of the lamella in such a way that - after being securely fastened to the main part - it can be provided with a sharp pointed edge by mechanical processing .

Die in den Ansprüchen 1 bis 7 angegebene(n) Leiste bzw. Leisten bzw. Leisten-Segmente können vorzugsweise aus einem harten Keramikwerkstoff hergestellt werden. Solche Keramik-Leisten sind frei von inneren Spannungen, so daß die fertige Lamelle außerordentlich formbeständig ist. Möglich ist aber auch die Verwendung von Metallen (z. B. Titan) für die Leisten. In diesem Fall ist jedoch in der Regel eine mechanische Bearbeitung erforderlich, mit der Gefahr, daß in den Leisten bzw. Leisten-Segmenten innere Spannungen entstehen. Diese können zur Folge haben, daß der Spitzenbereich der fertigen Lamelle sich nicht mit der erforderlichen Genauigkeit gerade erstreckt.The strip or strips or strip segments specified in claims 1 to 7 can preferably be produced from a hard ceramic material. Such ceramic strips are free of internal tension, so that the finished slat is extremely dimensionally stable. However, it is also possible to use metals (e.g. titanium) for the strips. In this case, however, mechanical processing is usually required, with the risk that internal stresses arise in the strips or strip segments. The consequence of this may be that the tip area of the finished lamella does not extend straight with the required accuracy.

Deshalb wird man in vielen Fällen die im Anspruch 8 angegebene Lösung bevorzugen. Anspruch 8 besagt mit anderen Worten folgendes: Man gibt dem Endbereich des Lamellen-Hauptteiles eine zum Ende hin verjüngende Form, versieht diesen Endbereich mit einer die Spitze bildenden Beschichtung aus einem Hartwerkstoff (z. B. aus einem Metall-Blech) und bearbeitet danach den Endbereich derart, daß eine im wesentlichen scharfe Spitz-Kante entsteht. Diese Bearbeitung erfolgt wiederum vorzugsweise durch Schleifen. Ein Vorteil dieser Methode ist, daß das Beschichtungsmaterial vor dem Befestigen am Hauptteil nicht mechanisch bearbeitet werden muß.Therefore, in many cases the solution specified in claim 8 will be preferred. In other words, claim 8 states the following: the end region of the main lamella part is given a shape that tapers towards the end, this end region is provided with a coating made of a hard material (for example, a metal sheet) that forms the tip, and then processed End area such that an essentially sharp pointed edge is created. This processing is again preferably carried out by grinding. An advantage of this method is that the coating material does not have to be mechanically processed before being attached to the main part.

Ein wichtiger weiterführender Erfindungsgedanke ist im Anspruch 12 angegeben. Danach erstreckt sich eine dünne Hartmetallschicht über das sich verjüngende Ende des Lamellen-Hauptteiles hinaus und erhält, wiederum vorzugsweise durch Schleifen, an seinem freien Ende eine scharfe Spitz-Kante. Diese zuletzt beschriebene Herstellungs-Methode hat sich bis jetzt in der Praxis am besten bewährt.An important further inventive idea is specified in claim 12. Then a thin hard metal layer extends over the tapered end of the The main part of the lamella also has a sharp pointed edge, again preferably by grinding, at its free end. This last-described manufacturing method has so far proven itself best in practice.

Verschiedene Ausführungsbeispiele werden nachfolgend anhand der Zeichnungen erläutert.Various exemplary embodiments are explained below with reference to the drawings.

Die Figur 1 zeigt einen schematischen Querschnitt durch einen Zwei-Schichten-Stoffauflauf.FIG. 1 shows a schematic cross section through a two-layer headbox.

Die Figur 2 ist eine Ansicht auf den Austrittspalt des Stoffauflaufes in Richtung des Pfeiles II der Figur 1.FIG. 2 is a view of the exit gap of the headbox in the direction of arrow II in FIG. 1.

Die Figuren 3 bis 8 zeigen unterschiedliche Ausführungen des Lamellen-Endbereiches in einer gegenüber den natürlichen Abmessungen stark vergrößerten Darstellung, jeweils im Querschnitt.Figures 3 to 8 show different versions of the slat end area in a greatly enlarged representation compared to the natural dimensions, each in cross section.

In Figur 1 erkennt man von einem an sich bekannten Zwei-Schicht-Stoffauflauf im wesentlichen nur den Bereich der sogenannten Düsenkammer, die zwei maschinenbreite Stoffströme zu einem Austrittspalt führt. Die Düsenkammer ist begrenzt durch zwei maschinenbreite Stromführungswände 1 und 1' sowie durch zwei Seitenwände 6 und 6', siehe Figur 2. Die beiden Stromführungswände 1 und 1' sind über je einen bekannten Turbulenzgenerator 5 mit einer mittleren stationären Trennwand 7 verbunden. Am auslaufseitigen Ende der Trennwand 7 ist, beispielsweise mittels eines Gelenkes 4, eine Lamelle 2 schwenkbar befestigt. Abweichend hiervon kann die Lamelle 2 auch starr an der Trennwand 7 befestigt sein. Die Lamelle 2 erstreckt sich gemäß Figur 1 von dem Gelenk 4 bis in den Bereich des Austrittspaltes oder über diesen hinaus. Gemäß Figur 2 erstreckt sich die Lamelle über die gesamte Maschinenbreite, also unmittelbar von der einen Seitenwand 6 bis zur anderen Seitenwand 6'. Somit hält die Lamelle 2 die zwei mit den Pfeilen 3 und 3' angedeuteten Stoffströme bis in den Bereich des Austrittspaltes voneinander getrennt. Abweichend von Figur 1 und 2 können mehrere Lamellen vorgesehen werden für mehr als zwei voneinander zu trennende maschinenbreite Stoffströme.In FIG. 1, from a two-layer headbox known per se, essentially only the area of the so-called nozzle chamber can be seen, which leads two machine-wide material flows to an exit gap. The nozzle chamber is delimited by two machine-wide flow guide walls 1 and 1 'and by two side walls 6 and 6', see FIG. 2. The two flow guide walls 1 and 1 'are each connected to a central stationary partition 7 via a known turbulence generator 5. At the outlet end of the partition 7, a lamella 2 is pivotally attached, for example by means of a joint 4. Deviating from this, the lamella 2 can also be rigidly attached to the partition 7. According to FIG. 1, the lamella 2 extends from the joint 4 to the region of the outlet gap or beyond it. According to FIG. 2, the lamella extends over the entire machine width, that is to say directly from one side wall 6 to the other side wall 6 '. Consequently the lamella 2 keeps the two material flows indicated by the arrows 3 and 3 'separated from one another up to the region of the outlet gap. Deviating from FIGS. 1 and 2, a plurality of lamellae can be provided for more than two machine-wide material flows to be separated from one another.

Die bis jetzt beschriebenen Bauteile des Stoffauflaufs werden in bekannter Weise sehr präzise gefertigt, so daß die lichte Weite a des gesamten Austrittspaltes über die Maschinenbreite gleichmäßig ist. Falls erforderlich, ist an der Wand 1 eine örtlich verformbare Leiste vorgesehen, um die lichte Weite a des Austrittspaltes zu vergleichmäßigen.The components of the headbox described so far are very precisely manufactured in a known manner, so that the clear width a of the entire outlet gap is uniform over the machine width. If necessary, a locally deformable strip is provided on the wall 1 in order to even out the clear width a of the outlet gap.

Es kommt nun darauf an, die Lamelle 2 und insbesondere deren spitz zulaufendes Ende, das sich im Bereich des Austrittspaltes befindet, ebenfalls sehr präzise zu fertigen. Dies bedeutet, daß insbesondere das spitz auslaufende Lamellenende möglichst exakt geradlinig von der einen Seitenwand 6 zur anderen Seitenwand 6' verlaufen muß, und zwar möglich exakt parallel zu den Auslaß-Enden der Stromführungswände 1 und 1'. Denn es ist entscheidend für das Erzielen einer hohen Papier-Qualität, daß die lichten Weiten b bzw. c der beiden Teil-Austrittspalte über die gesamte Maschinenbreite möglichst konstant sind.It is now important to manufacture the lamella 2 and in particular its tapered end, which is located in the area of the outlet gap, also very precisely. This means that, in particular, the tapering fin end must run as straight as possible from one side wall 6 to the other side wall 6 ', and possibly exactly parallel to the outlet ends of the flow guide walls 1 and 1'. It is crucial for achieving high paper quality that the clear widths b and c of the two partial exit gaps are as constant as possible over the entire machine width.

Dieses Ziel wird erreicht durch verschiedene spezielle Ausgestaltungen der Lamellen-Spitze, exemplarisch dargestellt in den Figuren 3 bis 8. In jeder dieser Figuren erkennt man das äußere Ende des vorzugsweise aus Kunststoff gefertigten Lamellen-Hauptteiles 8.3 bis 8.8. In allen diesen Figuren 3 bis 8 ist - zwecks Verdeutlichung der Einzelheiten - die Dicke d der Lamelle gegenüber den natürlichen Abmessungen wesentlich stärker vergrößert als die Abmessungen in Längsrichtung, beispielsweise die Länge L der gemäß Figur 3 die Spitze der Lamelle bildenden Leiste 9.3. Somit ist in Wirklichkeit der Winkel w der Spitz-Kante wesentlich kleiner als in der Zeichnung dargestellt. Die Spitz-Kante gleicht also eher einer messerartigen Schneide.This goal is achieved by means of various special configurations of the lamella tip, illustrated as an example in FIGS. 3 to 8. In each of these figures, one can see the outer end of the lamella main part 8.3 to 8.8, which is preferably made of plastic. In all of these FIGS. 3 to 8, the thickness d of the slat is increased considerably more than the dimensions in the longitudinal direction, for example to clarify the details, for example the length L of the strip 9.3 which forms the tip of the slat according to FIG. So in reality the angle w is the pointed edge much smaller than shown in the drawing. The pointed edge is more like a knife-like edge.

Gemäß den Figuren 3 bis 5 ist die Lamellen-Spitze gebildet aus einer vorgeformten ein- oder zweiteiligen Leiste 9.3, 9.4 bzw. 9.5. Gemäß Figur 3 ist die Leiste 9.3 mittels eines angeformten Steges in eine Nut des Lamellen-Hauptteiles 8.3 eingeklebt. Die Figur 4 zeigt ein umgekehrtes Beispiel: Hier ragt ein Steg des Lamellen-Hauptteiles 8.4 in eine Nut der die Spitze bildenden Leiste 9.4; diese kann auch zweiteilig ausgeführt sein, ähnlich der Figur 5.According to FIGS. 3 to 5, the lamella tip is formed from a preformed one or two-part strip 9.3, 9.4 or 9.5. According to FIG. 3, the strip 9.3 is glued into a groove of the main part 8.3 of the lamella by means of an integrally formed web. FIG. 4 shows a reverse example: Here, a web of the main part 8.4 of the lamella projects into a groove in the strip 9.4 forming the tip; this can also be made in two parts, similar to FIG. 5.

Gemäß Figur 6 ist an das Ende des Lamellen-Hauptteiles 8.6 einseitig ein dünnes Metall-Blech 9.6 angesetzt. Im Querschnitt gesehen ragt das Metall-Blech 9.6 über das freie Ende des Lamellen-Hauptteiles 8.6 hinaus; es ist mittels mechanischer Bearbeitung, z. B. Schleifen, mit einer scharfen Spitz-Kante versehen. Diese kann im Falle einer Beschädigung nachgeschliffen werden. Falls erforderlich kann das gesamte Lamellenende mit einer einheitlichen Schrägfläche versehen werden, z. b. Schleifen entlang der Ebene S.According to FIG. 6, a thin metal sheet 9.6 is attached to the end of the main lamella part 8.6. Viewed in cross section, the metal sheet 9.6 projects beyond the free end of the main lamella part 8.6; it is by means of mechanical processing, e.g. B. grinding, provided with a sharp pointed edge. In the event of damage, this can be reground. If necessary, the entire slat end can be provided with a uniform inclined surface, e.g. b. Loops along the level S.

Gemäß Figur 7 sind beide Seiten des sich verjüngenden Endes des Lamellen-Hauptteiles 8.7 mit einer harten Außenschicht 9.7 versehen und danach durch Schleifen entlang der Ebene S' mit einer scharfen Spitz-Kante versehen.According to FIG. 7, both sides of the tapering end of the main lamella part 8.7 are provided with a hard outer layer 9.7 and then provided with a sharp pointed edge by grinding along the plane S '.

Gemäß Figur 8 sind wiederum beide Seiten des sich verjüngenden Endes des Lamellen-Hauptteiles 8.8 mit dünnen Metall-Blech-Streifen 9.8 und 9.8' unterschiedlicher Breite beschichtet. Dabei ist wesentlich, daß der eine Metallstreifen 9.8' über den anderen 9.8 hinausragt, so daß dieser allein eine durch Schleifen hergestellte scharfe Spitz-Kante bildet.According to FIG. 8, both sides of the tapered end of the main lamella part 8.8 are again coated with thin metal-sheet strips 9.8 and 9.8 'of different widths. It is essential that one metal strip 9.8 'projects beyond the other 9.8 so that this alone forms a sharp pointed edge produced by grinding.

Bei allen Ausführungsbeispielen wird die gesamte Lamelle in hohem Maße gegen die Stoffsuspension chemisch beständig gemacht. Dadurch haben die vom Stoff berührten Außenflächen der Lamelle dauerhaft eine hohe Glätte, so daß das Hängenbleiben von Fasern oder von anderen Stoffpartikeln mit Sicherheit vermieden wird. Vorzugsweise hat die Außenfläche der Lamelle auch möglichst glatte Übergänge von dem (vorzugsweise aus Kunststoff gefertigten) Hauptteil zur Spitze. Unter Umständen kann aber an einem Übergang auch eine Stufe 10 vorgesehen werden; siehe Figur 5.In all of the exemplary embodiments, the entire lamella is made chemically resistant to a large extent to the material suspension. As a result, the outer surfaces of the lamella touched by the fabric have a permanently high level of smoothness, so that fibers or other material particles are reliably prevented from getting caught. The outer surface of the lamella preferably also has smooth transitions from the main part (preferably made of plastic) to the tip. Under certain circumstances, however, a level 10 can also be provided at a transition; see Figure 5.

Gemäß einem weiteren Erfindungsgedanken ist der Lamellen-Hauptteil aus einem mit Kohlefasern verstärkten Kunststoff gefertigt (Anspruch 17). Ein solcher Werkstoff verleiht dem Lamellen-Hauptteil eine sehr hohe thermische Stabilität. D. h., die Form des Lamellen-Hauptteils bleibt auch dann unverändert, wenn er mit (ggf. unterschiedlich) erwärmten Faserstoffsuspensions-Strömen in Berührung kommt. Insbesondere wird die Gleichmäßigkeit der Form des Lamellen-Endes wesentlich gesteigert, hauptsächlich in Verbindung mit der (gemäß Anspruch 8) durch eine relativ dünne Beschichtung gebildeten Lamellenspitze.According to a further inventive idea, the lamella main part is made of a plastic reinforced with carbon fibers (claim 17). Such a material gives the main part of the slats a very high thermal stability. In other words, the shape of the lamella main part remains unchanged even if it comes into contact with (possibly differently) heated fiber suspension streams. In particular, the uniformity of the shape of the lamella end is significantly increased, mainly in connection with the lamella tip formed by a relatively thin coating.

Wie oben erwähnt, kann man an einer der Stromführungswände 1 oder 1' eine örtlich verformbare Leiste vorsehen. Eine derartige Leiste, auch "Blende" genannt, ist ein seit langem bekanntes Hilfsmittel, um das Flächengewichts-Querprofil der herzustellenden Papierbahn zu vergleichmäßigen. Bei der Herstellung von mehrlagigen Papierbahnen treten jedoch Probleme auf, insbesondere wenn auf eine möglichst dünne Deckschicht Wert gelegt wird, die gleichzeitig die darunter liegende Lage sehr gleichmäßig abdecken soll. Wird nämlich eine örtliche Verformung der Blende des Stoffauflaufes vorgenommen, so kommt es zu einer Deformation des aus dem Stoffauflauf austretenden Stoffstrahles. Dabei wird vornehmlich die Dicke der Außenschicht beeinflußt, die jedoch eigentlich gleich dick bleiben soll.As mentioned above, a locally deformable strip can be provided on one of the current guiding walls 1 or 1 '. Such a bar, also called "aperture", has long been known as a tool to even out the basis weight cross profile of the paper web to be produced. However, problems arise in the production of multilayer paper webs, in particular if emphasis is placed on a cover layer which is as thin as possible and which at the same time should cover the layer underneath very uniformly. If a local deformation of the aperture of the headbox is carried out, the material jet emerging from the headbox is deformed. The thickness of the Influenced outer layer, which should actually remain the same thickness.

Ein zusätzliches Problem entsteht mit einer Blende am Düsenende des Stoffauflaufes dadurch, daß sich durch eine örtliche Verformung der Blende die Geometrie des Düsenendes ungleichmäßig ändert, wodurch es zu einer über die Maschinenbreite gleichmäßigen Auffächerung des Stoffstrahles kommt, was wiederum zu unterschiedlichen Vermischungsgraden der Schichten und auch zu einer ungewünschten über die Bahnbreite unterschiedlichen Beeinflussung der Faserorientierung führt.An additional problem arises with an orifice at the nozzle end of the headbox in that the geometry of the orifice end changes unevenly due to a local deformation of the orifice, which results in a uniform fanning out of the material jet across the machine width, which in turn leads to different degrees of mixing of the layers and also leads to an undesired influencing of the fiber orientation across the web width.

Neben den oben genannten Nachteilen der Blende am Düsenende bedingt eine Blendenverstelleinrichtung auch, daß die Düse des Stoffauflaufes, insbesondere beim Einsatz in Verbindung mit Doppelsiebformern, nicht genügend nahe an das Sieb herangeführt werden kann, wodurch ein unerwünscht langer, ungeführter Stoffstrahl in Kauf zu nehmen ist, was sich besonders bei mehrschichtigen Papieren qualitätsmindernd bemerkbar macht.In addition to the above-mentioned disadvantages of the orifice at the end of the nozzle, an orifice adjustment device also means that the headbox nozzle, particularly when used in conjunction with twin-wire formers, cannot be brought close enough to the wire, which means that an undesirably long, unguided material jet has to be accepted , which is particularly noticeable in the case of multilayer papers.

Deshalb besteht ein wichtiger weiterführender Gedanke der Erfindung darin, die (eine scharfe Spitzkante aufweisende) Lamelle vorzugsweise in einem Stoffauflauf anzuwenden, der keine verformbare Leiste, Blende oder dergleichen aufweist.An important further idea of the invention is therefore to use the lamella (which has a sharp pointed edge) preferably in a headbox which has no deformable strip, screen or the like.

Statt dessen wird gemäß Anspruch 18 vorgesehen, Korrekturen des Flächengewichts-Querprofiles dadurch zu ermöglichen, daß man in an sich bekannter Weise eine örtliche Änderung der Konzentration der Stoffsuspension herbeiführt, nämlich durch sektionale Beeinflussung der Suspensionszusammensetzung, insbesondere der Stoffdichte.Instead, it is provided according to claim 18 to enable corrections to the basis weight cross-section by bringing about a local change in the concentration of the pulp suspension in a manner known per se, namely by sectionally influencing the suspension composition, in particular the pulp density.

Zu diesem Zweck kann man unterschiedliche bekannte Systeme anwenden, z. B. das System gemäß DE 37 41 603 = US 4,909,904 (PA04490) oder das System gemäß DE 43 23 263 (PA05167). Bevorzugt werden jedoch (gemäß Anspruch 19 und Fig. 9) sektional über die Maschinenbreite verteilte Mischeinrichtungen, z. B. gemäß DE 42 11 291 C1 = US 5,316,383 (PA04928). Diese beruhen auf dem Prinzip, daß mehrere sektionale, d. h. über die Maschinenbreite verteilte Hauptstoffströme (Leitungen 14) vorhanden sind, und daß jedem sektionalen Hauptstoffstrom ein variabler sektionaler Neben-Stoffstrom mit anderer Stoffdichte (Leitungen 16) zugemischt wird. Dies erfolgt derart (z. B. durch Wahl eines geeigneten "Mischwinkels" a, Fig. 9), daß bei einer Veränderung der Größe des Neben-Stoffstromes die Größe des sektionalen Gemisch-Stoffstromes (Leitungen 14') unverändert bleibt. Dadurch kann man an einer bestimmten Stelle der Bahnbreite eine örtliche Korrektur des Bahn-Flächengewichtes herbeiführen, ohne an dieser Stelle die Faserorientierung zu verändern.Various known systems can be used for this purpose, e.g. B. the system according to DE 37 41 603 = US 4,909,904 (PA04490) or the system according to DE 43 23 263 (PA05167). However, preferred (according to claim 19 and Fig. 9) sectionally distributed across the machine width mixing devices, z. B. according to DE 42 11 291 C1 = US 5,316,383 (PA04928). These are based on the principle that a plurality of main streams of material (lines 14) distributed over the width of the machine are present, and that a variable secondary stream of material with a different material density (lines 16) is mixed into each main stream of material. This is done (for example, by choosing a suitable “mixing angle” a, FIG. 9) that when the size of the secondary material flow changes, the size of the sectional mixture material flow (lines 14 ') remains unchanged. This enables a local correction of the basis weight of the web to be carried out at a specific point in the web width without changing the fiber orientation at this point.

Ein weiterer Vorteil ist, daß das Düsenende des Stoffauflaufes sehr einfach gestaltet werden kann und somit fertigungstechnisch einen nur geringen Aufwand erfordert. Durch den Wegfall der Blenden-Verstelleinrichtungen kann der Stoffauflauf sehr nahe an das Sieb oder zwischen die Siebe herangeführt werden, wodurch der freie Stoffstrahl stark verkürzt und somit die Qualität des herzustellenden Mehrlagenpapiers noch weiter erhöht wird.Another advantage is that the nozzle end of the headbox can be designed very simply and therefore requires little effort in terms of production technology. By eliminating the orifice adjustment devices, the headbox can be brought very close to the screen or between the screens, which greatly shortens the free jet of fabric and thus further increases the quality of the multilayer paper to be produced.

Die Figur 9 zeigt den Stoffauflauf, der oben schon anhand der Figur 1 beschrieben wurde, zusammen mit einem schematisch dargestellten Leitungssystem zum Zuführen von verschiedenen Faserstoff-Suspensionen. Ein erster Hauptstoffstrom, bestehend aus einer ersten Papierstoffsorte, gelangt über eine Quer-Verteilleitung 11 und über eine davon abgezweigte Reihe von sektionalen Zuführleitungen 13 zu einem der beiden Turbulenzgeneratoren 5. Ein zweiter Hauptstoffstrom, bestehend aus einer anderen Papierstoffsorte, gelangt über eine Quer-Verteilleitung 12 und über eine davon abgezweigte Reihe von sektionalen Zuführleitungen 14, 14' zu dem anderen Turbulenzgenerator 5. Damit, falls erforderlich, das Flächengewichts-Querprofil der herzustellenden Papierbahn korrigiert werden kann, ist eine dritte Quer-Verteilleitung 15 vorgesehen zum Zuführen eines sogenannten Neben-Stoffstromes. Dieser besteht z. B. aus Verdünnungswasser oder aus der zweiten Papierstoffsorte, jedoch mit anderer, vorzugsweise geringerer Stoffdichte. Von der Quer-Verteilleitung 15 sind mehrere sektionale Zuführleitungen 16 mit je einem Steuerventil 17 abgezweigt. Jede der Leitungen 16 führt somit einen steuerbaren sektionalen Neben-Stoffstrom zu einer Mischstelle 18, wo er mit einem der sektionalen Hauptstoffströme vermischt wird. Abweichend von Figur 9 könnte zusätzlich noch folgendes vorgesehen werden: Weitere Zuführleitungen für einzeln steuerbare sektionale Neben-Stoffströme könnten in die sektionalen Zuführleitungen 13 für den ersten Hauptstoffstrom einmünden.FIG. 9 shows the headbox, which has already been described above with reference to FIG. 1, together with a schematically illustrated line system for feeding various fiber suspensions. A first main material stream, consisting of a first type of paper stock, reaches a one of the two turbulence generators 5 via a cross distribution line 11 and a branched branch row of section feed lines 13. A second main stock stream, consisting of another type of paper stock, reaches a cross distribution line 12 and over a branched series of sectional Feed lines 14, 14 'to the other turbulence generator 5. So that, if necessary, the basis weight cross profile of the paper web to be produced can be corrected, a third cross distribution line 15 is provided for feeding a so-called secondary material flow. This consists, for. B. from dilution water or from the second type of paper, but with a different, preferably lower consistency. A plurality of sectional supply lines 16, each with a control valve 17, are branched off from the transverse distribution line 15. Each of the lines 16 thus leads a controllable sectional secondary material flow to a mixing point 18, where it is mixed with one of the sectional main material flows. Deviating from FIG. 9, the following could also be provided: further feed lines for individually controllable sectional secondary material flows could open into the sectional feed lines 13 for the first main material flow.

Claims (19)

Mehrschichten-Stoffauflauf zum Zuführen von wenigstens zwei maschinenbreiten Faserstoffsuspensions-Strömen zur Formier-Sektion einer Papierherstellungsmaschine, mit den folgenden Merkmalen: a) Eine Düsenkammer ist begrenzt durch zwei maschinenbreite Stromführungswände (1, 1'), die an einem maschinenbreiten Austrittsspalt enden, und durch zwei Seitenwände (6, 6'); b) in der Düsenkammer ist wenigstens eine maschinenbreite Lamelle (2) vorgesehen mit der Funktion einer Trennwand, welche die wenigstens zwei Fasersuspensions-Ströme bis in den Bereich des Austrittsspaltes voneinander getrennt hält; c) die Lamelle (2) umfaßt einen (vorzugsweise aus Kunststoff gefertigten) Hauptteil (8) und eine aus einem Hartwerkstoff gebildete Spitze (9); d) dadurch gekennzeichnet, daß die Spitze (9.3 bis 9.5) als eine in das Hauptteil (8) integrierte und mit einer scharfen Spitz-Kante versehene Leiste ausgebildet ist. Multi-layer headbox for supplying at least two machine-wide fiber suspension streams to the forming section of a papermaking machine, with the following features: a) A nozzle chamber is delimited by two machine-wide flow guide walls (1, 1 ') which end at a machine-wide outlet gap and by two side walls (6, 6'); b) at least one machine-wide lamella (2) is provided in the nozzle chamber with the function of a partition which keeps the at least two fiber suspension streams separated from one another up to the region of the outlet gap; c) the lamella (2) comprises a main part (8) (preferably made of plastic) and a tip (9) formed from a hard material; d) characterized in that the tip (9.3 to 9.5) is designed as a strip integrated into the main part (8) and provided with a sharp pointed edge. Stoffauflauf nach Anspruch 1, dadurch gekennzeichnet, daß sich die Leiste über die gesamte Maschinenbreite erstreckt.Headbox according to claim 1, characterized in that the strip extends over the entire width of the machine. Stoffauflauf nach Anspruch 1, dadurch gekennzeichnet, daß die Leiste über die Maschinenbreite in Leisten-Segmente unterteilt ist.Headbox according to claim 1, characterized in that the bar is divided over the machine width into bar segments. Stoffauflauf nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß die die Spitze (9.3) bildende Leiste, im Querschnitt gesehen, einteilig ist.Headbox according to one of Claims 1 to 3, characterized in that the strip forming the tip (9.3) is in one piece, seen in cross section. Stoffauflauf nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß die die Spitze (9.5) bildende Leiste, im Querschnitt gesehen, zweiteilig ist.Headbox according to one of claims 1 to 3, characterized in that the strip forming the tip (9.5), viewed in cross section, is in two parts. Stoffauflauf nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß die Leiste aus Metall gebildet ist.Headbox according to one of claims 1 to 5, characterized in that the strip is formed from metal. Stoffauflauf nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß die Leiste aus einem Keramik-Werkstoff gebildet ist.Headbox according to one of claims 1 to 5, characterized in that the strip is formed from a ceramic material. Mehrschichten-Stoffauflauf nach dem Oberbegriff des Anspruches 1 (d. h. mit den Merkmalen a), b) und c) des Anspruches 1), dadurch gekennzeichnet, daß die Lamelle (2), wie an sich bekannt, sich zu ihrem Ende hin verjüngt, und daß die Spitze durch eine Beschichtung (9.6 - 9.8) gebildet ist, die auf wenigstens einer der beiden Seiten der Lamelle in diese integriert ist, und daß im Bereich der Beschichtung eine scharfe Spitz-Kante ausgebildet ist.Multi-layer headbox according to the preamble of claim 1 (ie with the features a), b) and c) of claim 1), characterized in that the lamella (2), as known per se, tapers towards its end, and that the tip is formed by a coating (9.6 - 9.8) which is integrated into the slat on at least one of the two sides thereof, and that a sharp pointed edge is formed in the area of the coating. Stoffauflauf nach Anspruch 8, dadurch gekennzeichnet, daß die Beschichtung (9.6, 9.8 und 9.8') durch ein mit der Lamelle (z. B. durch Kleben) verbundenes Metall-Blech gebildet ist.Headbox according to claim 8, characterized in that the coating (9.6, 9.8 and 9.8 ') is formed by a metal sheet connected to the lamella (e.g. by gluing). Stoffauflauf nach Anspruch 8, dadurch gekennzeichnet, daß die Beschichtung durch Bedampfen auf die Lamelle aufgebracht ist.Headbox according to claim 8, characterized in that the coating is applied to the lamella by vapor deposition. Stoffauflauf nach einem der Ansprüche 8, 9 oder 10 mit einer beidseitigen Beschichtung der Lamelle, dadurch gekennzeichnet, daß die Spitze mittels mechanischer Bearbeitung (z. B. durch Schleifen, durchgeführt nach dem Beschichten) geschärft ist.Headbox according to one of claims 8, 9 or 10 with a coating on both sides of the lamella, thereby characterized in that the tip is sharpened by means of mechanical processing (e.g. by grinding, carried out after coating). Stoffauflauf nach Anspruch 8, dadurch gekennzeichnet, daß die Spitze (9.8') durch ein Metall-Blech gebildet ist, das sich auf der einen Seite des Lamellen-Hauptteiles (8.8) befindet, sich über das Ende des Lamellen-Hauptteils erstreckt und mittels mechanischer Bearbeitung (z. B. Schleifen) geschärft ist.Headbox according to claim 8, characterized in that the tip (9.8 ') is formed by a metal sheet which is located on one side of the main lamella part (8.8), extends over the end of the main lamella part and by means of mechanical Machining (e.g. grinding) is sharpened. Stoffauflauf nach Anspruch 12, dadurch gekennzeichnet, daß die andere Seite des Endes des Lamellen-Hauptteils (8.8) ebenfalls eine Beschichtung (9.8) aufweist.Headbox according to claim 12, characterized in that the other side of the end of the lamella main part (8.8) also has a coating (9.8). Stoffauflauf nach einem der Ansprüche 1 bis 12, dadurch gekennzeichnet, daß die Spitze (9.3, 9.4, 9.6 - 9.8) stufenlos, d. h. wenigstens angenähert hydraulisch glatt, in das Lamellen-Hauptteil (8.3, 8.4, 8.6 - 8.8) integriert ist.Headbox according to one of claims 1 to 12, characterized in that the tip (9.3, 9.4, 9.6 - 9.8) is infinitely variable, i. H. at least approximately hydraulically smooth, is integrated in the main section of the lamella (8.3, 8.4, 8.6 - 8.8). Stoffauflauf nach einem der Ansprüche 1 bis 12, dadurch gekennzeichnet, daß die Außenseite der Lamelle (8.5, 9.5) am Übergang vom Hauptteil zur Spitze eine Stufe 10 aufweist.Headbox according to one of claims 1 to 12, characterized in that the outside of the lamella (8.5, 9.5) has a step 10 at the transition from the main part to the tip. Stoffauflauf nach Anspruch 8, dadurch gekennzeichnet, daß das sich verjüngende Lamellenende beidseitig Beschichtungen (9.8, 9.8') aufweist, und daß die Enden der Beschichtungen bezüglich der Strömungsrichtung zueinander versetzt angeordnet sind (Fig. 8).Headbox according to claim 8, characterized in that the tapering lamella end has coatings (9.8, 9.8 ') on both sides, and that the ends of the coatings are arranged offset with respect to the flow direction (Fig. 8). Stoffauflauf nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, daß das Lamellen-Hauptteil (8.3 - 8.8) aus einem vorzugsweise thermisch stabilen Kunststoff, z. B. aus einem mit Kohlefasern verstärkten Kunststoff hergestellt ist.Headbox according to one of claims 1 to 6, characterized in that the lamella main part (8.3 - 8.8) made of a preferably thermally stable plastic, e.g. B. is made of a plastic reinforced with carbon fibers. Stoffauflauf nach einem der Ansprüche 1 bis 17, gekennzeichnet durch die folgenden Merkmale: a) die Enden der Stromführungswände (1, 1') sind frei von örtlich verstellbaren oder verformbaren Leisten; b) zum Korrigieren des Flächengewichts-Querprofiles der herzustellenden Bahn sind mehrere über die Maschinenbreite verteilte Leitungen vorgesehen zum Zumischen variabler "Neben-Stoffströme" mit einer vom "Haupt-Stoffstrom" abweichenden Stoffdichte. Headbox according to one of claims 1 to 17, characterized by the following features: a) the ends of the current guide walls (1, 1 ') are free of locally adjustable or deformable strips; b) in order to correct the basis weight cross-section of the web to be produced, several lines distributed over the machine width are provided for admixing variable "secondary material flows" with a material density deviating from the "main material flow". Stoffauflauf nach Anspruch 18, gekennzeichnet durch eine an sich bekannte Anordnung, welche bei einer Veränderung der Größe eines Neben-Stoffstromes die Größe des Gemisch-Stoffstromes konstant hält.Headbox according to claim 18, characterized by a known arrangement which keeps the size of the mixture stream constant when changing the size of a secondary stream.
EP95117555A 1994-11-10 1995-11-08 Multi-layer headbox Expired - Lifetime EP0711869B1 (en)

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DE4440079 1994-11-10
DE4440079A DE4440079C2 (en) 1994-11-10 1994-11-10 Multi-layer headbox

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EP0711869A2 true EP0711869A2 (en) 1996-05-15
EP0711869A3 EP0711869A3 (en) 1997-04-16
EP0711869B1 EP0711869B1 (en) 2002-03-27

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AT (1) ATE215144T1 (en)
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AT406171B (en) * 1998-02-05 2000-03-27 Andritz Patentverwaltung DEVICE FOR SUPPLYING A FIBER FIBER SUSPENSION TO A DRAINAGE DEVICE
EP1365067A1 (en) * 2002-05-25 2003-11-26 Voith Paper Patent GmbH Forming section
EP0939842B2 (en) † 1996-06-12 2006-06-28 Metso Paper Karlstad Aktiebolag A multilayer headbox for a papermaking machine
EP1798337A1 (en) * 2004-10-05 2007-06-20 Mitsubishi Heavy Industries, Ltd. Flow sheet for paper machine and method of manufacturing the same
WO2021063556A1 (en) * 2019-09-30 2021-04-08 Voith Patent Gmbh Lamella for a headbox, and method for producing a lamella

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DE10051802A1 (en) * 2000-10-18 2002-04-25 Voith Paper Patent Gmbh Slat of a headbox of a paper, cardboard or tissue machine
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DE10133552A1 (en) * 2001-07-11 2003-01-23 Voith Paper Patent Gmbh Stock inlet, for a papermaking/cardboard production machine, has a blade at the outflow with a gap between it and the side walls and an angled chamfer to prevent a pulp build-up
DE10256510A1 (en) * 2002-12-04 2004-06-24 Voith Paper Patent Gmbh Headbox of a paper or board machine for the production of a fibrous web
DE10326304A1 (en) * 2003-06-11 2005-02-03 Voith Fabrics Patent Gmbh Method and device for producing a tissue web
CN101934172B (en) 2004-11-05 2016-06-08 唐纳森公司 Filter medium and structure
US8021457B2 (en) 2004-11-05 2011-09-20 Donaldson Company, Inc. Filter media and structure
US8057567B2 (en) 2004-11-05 2011-11-15 Donaldson Company, Inc. Filter medium and breather filter structure
EP1846136A2 (en) 2005-02-04 2007-10-24 Donaldson Company, Inc. Aerosol separator
WO2006091594A1 (en) * 2005-02-22 2006-08-31 Donaldson Company, Inc. Aerosol separator
FI20065639L (en) * 2006-10-05 2008-04-06 Metso Paper Inc Lamella in an outlet box in a paper machine or equivalent
EP2117674A1 (en) 2007-02-22 2009-11-18 Donaldson Company, Inc. Filter element and method
EP2125149A2 (en) 2007-02-23 2009-12-02 Donaldson Company, Inc. Formed filter element
DE102007036535A1 (en) 2007-08-02 2009-02-05 Voith Patent Gmbh Headbox for machine for manufacturing multi-fiber fabric has lamella tip axis arranged at angle to main lamella axis of main lamella part so that free jet is deflected in desired direction
DE102008043145A1 (en) * 2008-10-24 2010-04-29 Voith Patent Gmbh Two-layer casserole for a machine for producing a two-layer fibrous web
EP2199459A1 (en) 2008-12-16 2010-06-23 Voith Patent GmbH Sheet composition system for a machine for producing a multiple layer sheet of fibrous material
US8267681B2 (en) 2009-01-28 2012-09-18 Donaldson Company, Inc. Method and apparatus for forming a fibrous media
WO2012103547A1 (en) 2011-01-28 2012-08-02 Donaldson Company, Inc. Method and apparatus for forming a fibrous media
EP2668326B1 (en) 2011-01-28 2016-03-30 Donaldson Company, Inc. Method and apparatus for forming a fibrous media
EP2707542A4 (en) * 2011-05-11 2015-04-08 Hollingsworth & Vose Co Systems and methods for making fiber webs
EP2736713B1 (en) 2011-07-27 2019-06-26 Hollingsworth & Vose Company Method and system for making fiber webs
EP2736712A4 (en) 2011-07-27 2015-03-11 Hollingsworth & Vose Co Systems and methods for making fiber webs
EP3861168B1 (en) 2018-10-01 2024-03-13 Outlier Solutions, Llc Re-pulpable insulated paper products and methods of making and using the same
WO2021067355A1 (en) 2019-10-01 2021-04-08 Outlier Solutions Llc Apparatus, systems and methods for making re-pulpable insulated paper products

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0939842B2 (en) † 1996-06-12 2006-06-28 Metso Paper Karlstad Aktiebolag A multilayer headbox for a papermaking machine
AT406171B (en) * 1998-02-05 2000-03-27 Andritz Patentverwaltung DEVICE FOR SUPPLYING A FIBER FIBER SUSPENSION TO A DRAINAGE DEVICE
EP1365067A1 (en) * 2002-05-25 2003-11-26 Voith Paper Patent GmbH Forming section
EP1798337A1 (en) * 2004-10-05 2007-06-20 Mitsubishi Heavy Industries, Ltd. Flow sheet for paper machine and method of manufacturing the same
EP1798337A4 (en) * 2004-10-05 2009-02-18 Toray Industries Flow sheet for paper machine and method of manufacturing the same
US7785446B2 (en) 2004-10-05 2010-08-31 Toray Industries, Inc. Flow sheet for paper machine and method of manufacturing the same
WO2021063556A1 (en) * 2019-09-30 2021-04-08 Voith Patent Gmbh Lamella for a headbox, and method for producing a lamella
CN114555882A (en) * 2019-09-30 2022-05-27 福伊特专利有限公司 Sheet for a headbox and method for producing a sheet
CN114555882B (en) * 2019-09-30 2024-06-07 福伊特专利有限公司 Sheet for a headbox and method for producing a sheet

Also Published As

Publication number Publication date
ATE215144T1 (en) 2002-04-15
EP0711869B1 (en) 2002-03-27
DE59510123D1 (en) 2002-05-02
EP0711869A3 (en) 1997-04-16
DE4440079A1 (en) 1996-05-23
DE4440079C2 (en) 1997-10-02
US5645689A (en) 1997-07-08

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